Radial seal air filter

ABSTRACT

Various example embodiments relate to a filtration system. The filtration system comprises a housing having a first housing end and a second housing end. The housing defines a central compartment therein. The housing comprises a first alignment portion disposed on the first housing end. The filtration system further comprises a filter element positioned within the central compartment of the housing. The filter element has a first filter end and a second filter end. The filter element comprises filter media and a second alignment portion disposed on the first filter end. The second alignment portion is complementary to the first alignment portion. The installation of the filter element within the housing causes the first alignment surface and the second alignment surface to align to provide for engagement of a radial seal between the filter element and the housing.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 16/631,974, filed Jan. 17, 2020, which is the national stage ofPCT Application No. PCT/US2018/042589, filed Jul. 18, 2018, which claimsthe benefit of and priority to U.S. Provisional Patent Application No.62/535,068, filed Jul. 20, 2017. The contents of these applications areincorporated herein by reference in their entirety and for all purposes.

TECHNICAL FIELD

The present application relates to filter elements for filtering fluidsin internal combustion engine systems or the like.

BACKGROUND

Internal combustion engines generally combust a mixture of fuel (e.g.,gasoline, diesel, natural gas, etc.) and air. Prior to entering theengine, the intake air is typically passed through a filtration systemto remove contaminants (e.g., dust, water, oil, etc.) from the intakeair. The filtration system includes a filter element having filtermedia. As the air passes through the filter media of the filter element,the filter media removes at least a portion of the contaminants in theair thereby preventing unwanted contaminants from entering the internalcombustion engine. In some cases, unauthorized or non-genuinereplacement filter elements may be installed in the filtration systemsduring servicing operations. The unauthorized and non-genuinereplacement filter elements may be of inferior quality to genuine,authorized filter elements. Thus, the use of unauthorized or non-genuinereplacement filter elements may cause damage to the engine by allowingcontaminants past the filter element.

Filter elements often include a seal member that is compressed against acomponent of the filtration system housing or another portion of thefiltration system. The seal member forms a seal between the filtrationsystem housing and the filter element, thereby preventing fluid frombypassing the filter element (e.g., for air to bypass an air filterelement). If an improper filter element (i.e., a non-authorized ornon-genuine filter element) is installed in a filtration system, theseal member of the filter element may not form a proper seal, and fluidmay bypass the filter element causing damage to downstream components.

SUMMARY

Various example embodiments relate to a filtration system. Thefiltration system comprises a housing having a first housing end and asecond housing end. The housing defines a central compartment therein.The housing comprises a first alignment portion disposed on the firsthousing end. The filtration system further comprises a filter elementpositioned within the central compartment of the housing. The filterelement has a first filter end and a second filter end. The filterelement comprises filter media and a second alignment portion disposedon the first filter end. The second alignment portion is complementaryto the first alignment portion. The installation of the filter elementwithin the housing causes the first alignment surface and the secondalignment surface to align to provide for engagement of a radial sealbetween the filter element and the housing.

Another example embodiment relates to a filter element. The filterelement is configured to be positioned within a central compartment of ahousing. The filter element has a first filter end and a second filterend. The filter element comprises filter media and a first alignmentportion disposed on the first filter end. The first alignment portion iscomplementary to a second alignment portion on the housing. Theinstallation of the filter element within the housing causes the firstalignment surface and the second alignment surface to align so as toprovide for engagement of a radial seal between the filter element andthe housing.

Another example embodiment relates to a filtration system. Thefiltration system comprises a housing having a first housing end and asecond housing end. The housing defines a central compartment therein.The housing comprises a first alignment portion disposed on the firsthousing end. The first alignment portion comprises a first surface witha first height that varies in a z-direction. The z-direction isperpendicular to an x-y plane. The x-y plane is normal to a central axisof the housing. A filter element is positioned within the centralcompartment of the housing. The filter element has a first filter endand a second filter end. The filter element comprises a filter media anda second alignment portion disposed on the first filter end. The secondalignment portion comprises a second surface with a second height thatvaries in the z-direction. The installation of the filter element withinthe housing causes the second surface and the first surface of the firstalignment portion to align so as to provide for engagement of a radialseal between the filter element and the housing.

These and other features, together with the organization and manner ofoperation thereof, will become apparent from the following detaileddescription when taken in conjunction with the accompanying drawings,wherein like elements have like numerals throughout the several drawingsdescribed below.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A shows a perspective view of a filter element according to anexample embodiment.

FIG. 1B shows a perspective view of a housing complementary to thefilter element of FIG. 1A.

FIG. 1C shows a cross-sectional, side view of a filtration systemincluding the filter element of FIG. 1A and the housing of FIG. 1B.

FIG. 2 shows a cross-sectional, perspective view of the radial sealingsurface of the filtration system of FIG. 1C.

FIG. 3A shows a perspective view of a filter element according to afurther example embodiment.

FIG. 3B shows a cross-sectional, perspective view of a housingcomplementary to the filter element of FIG. 3A.

FIG. 3C shows a cross-sectional, exploded view of a filtration systemincluding the filter element of FIG. 3A and the housing of FIG. 3B.

FIG. 3D shows a cross-sectional, side view of a filtration systemincluding the filter element of FIG. 3A and the housing of FIG. 3B.

FIG. 4A shows a perspective view of a filter element according toanother example embodiment.

FIG. 4B shows a perspective view of a housing complementary to thefilter element of FIG. 4A.

FIG. 4C shows a cross-sectional, side view of a filtration systemincluding the filter element of FIG. 4A and the housing of FIG. 4B.

FIG. 5A shows a perspective view of a filter element according to stillanother example embodiment.

FIG. 5B shows a perspective view of a housing complementary to thefilter element of FIG. 5A.

FIG. 5C shows a perspective view of a filtration system including thefilter element of FIG. 5A and the housing of FIG. 5B.

FIG. 5D shows a cross-sectional, perspective view of a portion of thefiltration system of FIG. 5C.

FIG. 6A shows a perspective view of a filter element according to stillanother example embodiment.

FIG. 6B shows a perspective view of a housing complementary to thefilter element of FIG. 6A.

FIG. 6C shows a perspective view of a filtration system including thefilter element of FIG. 6A and the housing of 6B.

FIG. 6D shows a cross-sectional, perspective view of a portion of thefiltration system of FIG. 6C.

FIG. 7A shows a perspective view of a filtration system according to afurther example embodiment.

FIG. 7B shows a cross-sectional, perspective view of the filtrationsystem of FIG. 7A.

FIG. 8A shows a perspective view of a filtration system including akeyed center tube interface according to a further example embodiment.

FIG. 8B shows a perspective view of a filtration system including acenter tube interface according to a further example embodiment.

FIG. 9A shows a cross-sectional, side view of a filtration systemincluding a central sealing rib according to an example embodiment.

FIG. 9B shows a perspective view of a housing shown in FIG. 9A.

FIG. 9C shows a cross-sectional, side view of a filtration systemincluding a central sealing rib according to another example embodiment.

DETAILED DESCRIPTION

Referring to the figures generally, a filtration system having bothsubstantially lateral planar (e.g., perpendicular with an axial centralaxis of the filter element) portion(s) and alignment portion(s) disposedon a filter element and a housing is described. As used herein, the term“alignment portion” or “alignment surface” refers to a surface that isangled relative to the central axis, arched, contoured, comprised ofmultiple intersecting laterally planar sub-portions, non-lateral planarsub-portions, and/or non-normal to the central axis sub-portions, etc.In other words, the alignment portion(s) include a surface or surfaceswith varying height in a z-direction with respect to an x-y plane, withthe x-y plane being normal to the central axis of the housing and/orfilter element. Generally, the installation of the filter element withinthe housing causes the alignment surfaces to align, which providessufficient travel for engagement of a radial seal between the filterelement and the housing wall. Variations of a filter element having oneor more alignment portions and a housing having a complementaryalignment portion(s) are described. Accordingly, the radial seal betweenthe filter element and center of the housing will vary in thez-direction (where the x-y plane is normal to the central axis of thefilter element and/or housing). The alignment surfaces of the housingand the filter element prevent proper filtration system function andsealing when an unauthorized replacement filter element having a flataxial seal member is installed in the housing. As will be appreciated,the variation of the filtration system may include either end of thefilter element or housing (e.g., filter housing) being open or closed;either end of the filter element or housing being an alignment portion;and either end of the filter element or housing being non-parallel toeach other.

Referring to FIG. 1A, a perspective view of a filter element 102 isshown, according to an example embodiment. The filter element 102includes filter media 108 disposed between a first end cap 106 and asecond end cap 110. As shown in FIG. 1A, the first end cap 106 isdisposed on a bottom end of the filter element 102, and the second endcap 110 is disposed on a top end of the filter element 102.Alternatively, in some embodiments, the first end cap 106 is disposed onthe top end of the filter element 102 and the second end cap 110 isdisposed on the bottom end of the filter element 102. As shown in FIG.1A, the first end cap 106 includes a substantially lateral planarsurface that is substantially normal to the central axis of the filterelement 102 and an alignment portion (e.g., alignment surface,protrusion, etc.) 104, in the form of a contoured surface, which isextruded in a direction perpendicular to the central axis such that aportion of the surface is in a direction normal to the central axis anda portion of the surface (e.g., direction of indentation) is in adirection parallel to the central axis of the filter element 102. Asshown in FIG. 1A, the alignment portion 104 is a depressed surface. Insome embodiments, the alignment portion 104 may be in the form of aprotruding surface. As will be appreciated, when the first end cap 106and alignment portion 104 align with a housing having a complementaryalignment portion, it provides sufficient travel for engagement of aradial seal between the filter element 102 and center of the housingwall. In some arrangements, the radial seal is formed around thelocation of the engagement of the center of the vertical axis of thefilter housing wall and the filter element 102.

Although the filter media 108 is shown arranged as a cylindrical filterblock having a circular cross-sectional shape, the filter media 108 canbe arranged in other shapes (e.g., racetrack or oval shapes). The filtermedia 108 may comprise, for example, pleated filter media 108 arrangedin a panel or pleat block, corrugated filter media (often referred to aspleated filter media 108) that is arranged in a panel, a block, acylinder, or the like, other arrangements.

In one set of embodiments, the filter media 108 is generally formed by aflat sheet of filter media 108 and a formed sheet of filter media 108.The formed sheet includes a plurality of crests formed by a curvesand/or pleats in the sheet. The plurality of crests form tetrahedronchannels between the formed sheet and the flat sheet. Embossments, suchas dimples, are provided on the crests formed by the curves and/orpleats. The embossments help to maintain spacing between adjacent layersof the filter media (i.e., between the formed sheet and the flat sheet),thereby increasing dust holding capacity and lowering pressure drop oversimilarly configured filter media not having the embossments. In somearrangements, the filter media 108 is pleated along a plurality of bendlines. The bend lines extend axially along an axial direction andinclude a first set of bend lines extending from the upstream inletaxially towards the downstream outlet, and a second set of bend linesextending from the downstream outlet axially towards the upstream inlet.

In some arrangements, the filter media 108 includes a plurality of inlettetrahedron flow channels and a plurality of outlet tetrahedron flowchannels. The inlet tetrahedron merge in a central portion of the filtermaterial, thereby allowing axial cross-flow of air between the inlettetrahedron channels prior to the air passing through the filter media.Such an arrangement provides for additional dust loading on the upstreamside of the media, which increases filter capacity. Specificarrangements of such tetrahedral filter media are further described inU.S. Pat. No. 8,397,920. In an alternate arrangement, the flow channelscomprise flutes that are alternately sealed at the upstream anddownstream ends.

The filter element 102 is substantially rigid such that the shape of thefilter element 102 is substantially maintained during installation anduse. The rigidity may be achieved through the use of a frame (e.g., ahard urethane frame, an injection molded frame, a thermoformed frame, aroto-molded frame, a 3D printed frame, a stamped metal frame, etc.) orstiffening members (e.g., pleating stabilization beads, spraying with astiffening agent, such as BASF® Elastocast 55090, polyurethane, or thelike, etc.).

Referring to FIG. 1B, a perspective view of a housing 120 complementaryto the filter element 102 of FIG. 1A is shown, according to an exampleembodiment. The housing 120 includes a complementary alignment portion122 formed in the housing 120, an inlet tube 124, an outlet tube 126, afirst housing end 128, and a second housing end 129. The alignmentportion 122 is a surface complementary to the alignment portion 104 ofthe filter element 102. As shown in FIG. 1B, the alignment portion 122in the form of a contoured surface protrudes complementary to thedepressed surface of the alignment portion 104 of the filter element102. The single alignment portion 122 acts as a keying feature so thatthe filter element 102 can only be installed in one orientation. In someembodiments, the alignment portion 122 may be in the form of a depressedsurface and varies in height due to the contoured surfaces. Thealignment portion 122 may be a hemispherical, cylindrical, sidewayscylindrical, or other generally similar shapes.

As shown in FIG. 1B, the housing 120 includes an integrated 90° inlettube 124. The housing 120 also includes an integrated 90° outlet tube126 that is fluidly connected to the first housing end (e.g., bottomend) 128. The outlet tube 126 protrudes into the cylindrical housing 120inner volume and the contour of the alignment portion 122 formed in thefirst housing end 128 matches the profile of the outlet tube 126.Although the housing 120 is shown arranged as a cylindrical housinghaving a circular cross-sectional shape, the housing 120 can be arrangedin other shapes to receive the filter element 102. The second housingend (e.g., top end) 129 is structured to receive a cover (not shown) toand enclose the filter element 102 within the housing 120. In somearrangements, the cover sealingly engages the second end cap 110 of thefilter element 102 and/or sealingly engages with the housing 120.

Referring to FIG. 1C, a cross-sectional, side view of a filtrationsystem including the filter element of FIG. 1A and the housing of FIG.1B is shown, according to an example embodiment. When the filtrationsystem 100 is in the assembled state, the filter element 102 ispositioned within a central compartment of the housing 120. The housingcover 130 encloses the filter element 102 within the housing 120. Insome arrangements, the housing cover 130 may sealingly engaged with thesecond end cap 110 of the filter element 102 and the second housing end129 of the housing 120. In some arrangements, a sealing member contactsthe second housing end 129 of the housing such that when the top housingcover 130 is secured to the housing 120, the seal member is compressedbetween the housing 120 and the top housing cover 130.

As shown in FIG. 1C, the alignment portion 104 of the filter element 102and the alignment portion 122 of the housing 120 are structured suchthat an unauthorized filter with a substantially lateral planar bottomsurface (or uncomplimentary alignment portion) cannot sit flush with thealignment portion 122 disposed on the bottom surface of the housing 120.As shown in FIG. 1C, the filter element 102 and the complementaryhousing 120 align to provide sufficient travel for engagement of aradial seal between the filter element 102 and the housing 120.Specifically, the alignment portion 104 of the filter element 102 andthe alignment portion 122 of the housing 120 align to seal via thedisposition of the filter element 102 in the first housing end 128 ofthe housing 120. As will be appreciated, the engagement of the specificalignment portions 104, 122 makes it difficult, if not impossible, toradially or axially seal without using a filter that matches thehousing. While the alignment portion 104 of the filter element 102 andthe alignment portion 122 of the housing 120 are shown to align andengage, in some arrangements, the alignment portion 104 of the filterelement 102 and the alignment portion 122 of the housing 120 only needto align, and not engage (e.g., a gap may exist), to provide for theengagement of the radial seal between the filter element 102 and thehousing 120.

Generally, when the filtration system 100 is assembled, the filtrationsystem 100 filters air and provides the filtered air to a device, suchas an internal combustion engine. The filtration system 100 receives airto be filtered through the inlet tube 124. The air passes from the inlettube 124, into the housing 120, and through the filter media 108 of thefilter element 102. As the air passes through the filter media 108, thefilter media 108 removes contaminants (e.g., dirt, dust, moisture, etc.)contained in the air. The alignment of the first end cap 106 and thealignment portion 122 of the housing 120 provide sufficient travel forengagement of a radial seal between the filter element 102 and thehousing 120. In some arrangements, the engagement of the radial sealoccurs between the inner diameter of the filter element 102 and thehousing 120. In other arrangements, the engagement of the radial sealoccurs between the outer diameter of the filter element 102 and thehousing 120. The radial seal ensures that the filtered air that passesthrough the center of the filter element 102 travels out of the outlettube 126. As the filter element 102 filters the air, the filter media108 captures the contaminants. Accordingly, the filter element 102requires periodic replacement as the filter media 108 reaches capacity.

Referring to FIG. 2, a cross-sectional, perspective view of the radialsealing surface of the filtration system 100 of FIG. 1C is shown. Asshown in FIG. 2, the engagement of the filter element 102 and thecomplementary housing 120 forms a radial seal 202. The filter element102 that engages the housing 120 to form the radial seal 202 comprises aflexible material, such as urethane, and is configured to be compressedagainst the housing 120 to form the radial sealing surface 202 against.The alignment portion 122 of the housing 120 and the alignment portion104 of the filter element 102 align to form the angled inner sealingwall 204. As used herein, the term “angled” refers to a surface that isangled with respect to a lateral plane that is substantially normal to acentral axis of the filter element 102. The alignment portion 104 of thefilter element 102 follows the contour of the alignment portion 122 ofthe housing 120 to form the angled inner sealing wall 204. Accordingly,the angled inner sealing wall 204 is such that one side of angled innersealing wall 204 is higher than on the other side of the angled innersealing wall 204. The height gap 206 caused by the difference in theheights of the sides of the angled inner seal prevents the axial sealingof the filter element 102 and the complementary housing 120. Whenproperly sealed, as shown in FIG. 2, the air will flow 210 through thefilter element 102 and out of the outlet tube 126 of the housing. Insome embodiments, the engagement of the alignment portions provides foran axial seal between the filter element 102 and the first housing end128.

Referring to FIG. 3A, a perspective view of a filter element 302 isshown, according to another example embodiment. The filter element 302is similar to the filter element 102. A difference between the filterelement 302 and the filter element 102 is the arrangement of alignmentportions of the filter element 302. Accordingly, like numbering is usedto designate like parts between the filter element 302 and the filterelement 102. The first end cap 106 includes a substantially lateralplanar surface that is substantially normal to the central axis of thefilter element 102 and two alignment portions (e.g., alignment surface,protrusion, etc.) 304, 306 in the form of contoured surfaces that aresubstantially curved with respect to the central axis of the outlet tube126. As shown in FIG. 3A, the arrangement of the alignment portion ofthe filter element 302 is a first alignment portion 304 and a secondalignment portion 306 disposed opposite of each other on the first endcap 106. In other words, the filter element 302 includes a matchingcontouring surface at locations on opposite sides of the first end cap106 of the filter element 302. As will be appreciated, the first end cap106 and alignment portions 304, 306 align with a housing havingcomplementary alignment portions to provide sufficient travel forengagement of a radial seal between the filter element 302 and thehousing 320. As shown in FIG. 3A, the alignment portions 304, 306 aredepressed curved surfaces. In some embodiments, the alignment portions304, 306 may be in the form of protruding curved surfaces.

The filter element 302 further includes a second end cap 110 and filtermedia 108. Although the filter media is shown arranged as a cylindricalfilter block having a circular cross-sectional shape, the filter media108 can be arranged in other shapes. The filter element 302 issubstantially rigid such that the shape of the filter element 302 ismaintained. The rigidity may be achieved through the use of a frame(e.g., a hard urethane frame, an injection molded frame, a thermoformedframe, a roto-molded frame, a 3D printed frame, a stamped metal frame,etc.) or stiffening members (e.g., pleating stabilization beads,spraying with a stiffening agent, such as BASF® Elastocast 55090,polyurethane, or the like, etc.).

Referring to FIG. 3B, a perspective view of a housing 320 complementaryto the filter element 302 of FIG. 3A is shown. The housing 320 issimilar to the housing 120. A difference between the housing 320 and thehousing 120 is the arrangement of alignment portions of the housing 320.Accordingly, like numbering is used to designate like parts between thehousing 320 and the housing 120. As shown in FIG. 3B, the housing 320includes a first alignment portion 322 formed in the housing 320, asecond alignment portion 326 formed in the housing 320, an outlet tube126, and a first housing end 128. The first alignment portion 322 is asurface complementary to the first alignment portion 304 of the filterelement 302. The second alignment portion 326 is a surface complementaryto the second alignment portion 326 of the filter element 302. The firstalignment portion 322 and the second alignment portion 326 are in theform of a contoured surface that protrudes complementary to thedepressed surfaces of the first alignment portion 304 and the secondalignment portion 306 of the filter element 302. As will be appreciated,the first alignment portions 304, 322 are interchangeable with thesecond alignment portions 306, 326 such that the filter element 302 canonly be installed in two orientations.

In some embodiments, one or both of the first alignment portion 322 andthe second alignment portion 326 may be in the form of a depressedsurface and varies in height due to the contoured surfaces. As shown inFIG. 3B, the housing 320 includes an integrated 90° outlet tube 126. Theoutlet tube 126 protrudes into the cylindrical housing 320 inner volumeand the first housing end 128 profile matches the profile of the outlettube 126 and first alignment portion 322 and the second alignmentportion 326 contour. Although the housing 320 is shown arranged as acylindrical housing having a circular cross-sectional shape, the housing320 can be arranged in other shapes to receive the filter element 302.The housing includes a second housing end (not shown) structured toreceive a cover (not shown) to enclose the filter element 302 within thehousing 320. In some arrangements, the cover may sealingly engage thesecond end cap of the filter element 302.

Referring to FIG. 3C, a cross-sectional, an exploded view of afiltration system 300 is shown according to an example embodiment. Thefiltration system 300 includes the filter element 302 of FIG. 3A, thehousing 320 of FIG. 3B, and a housing cover 130. In some arrangements,the housing cover 130 is structured to sealingly engage the second endcap 110 of the filter element 302.

Referring to FIG. 3D, a cross-sectional, side view of the filtrationsystem 300 assembled is shown. When the filtration system 300 is in theassembled state, the filter element 302 is positioned within a centralcompartment of the housing 320. The housing cover 130 encloses thefilter element 302 within the housing 320. In some arrangements, thehousing cover 130 may sealingly engage the second end cap 110 of thefilter element 302 and the second housing end 129 of the housing 120. Asshown in FIG. 3D, the housing cover 130 is a closed end cap, however, inother embodiments, the housing cover 130 is an open end cap. In somearrangements, a sealing member contacts the second housing end 129 ofthe housing such that when the top housing cover 130 is secured to thehousing 320, the seal member is compressed between the housing 320 andthe top housing cover 130 to form a seal. In another arrangement, thehousing cover 130 comprises a cylindrical wall that protrudes into thecenter of the filter element 302 to form a radial seal on the innerdiameter of the second end cap 110 of the filter element 302. In somearrangements, the radial seal is formed around the location of theengagement of the center of the vertical axis of the filter housing wall320 and the filter element 302.

As shown in FIG. 3D, the first alignment portion 322 and the secondalignment portion 326 of the housing 320 are in the form of a contouredsurface that protrude complementary to the depressed surfaces of thefirst alignment portion 304 and the second alignment portion 306 of thefilter element 302. As shown in FIG. 3D, the filter element 302 and thefirst housing end 128 of the complementary housing 320 align to providesufficient travel for engagement of a radial seal between the filterelement 302 and the housing 320. Specifically, the first alignmentportion 322 and the second alignment portion 326 of the housing 320 andcomplementary depressed surfaces of the first alignment portion 304 andthe second alignment portion 306 of the filter element 302 align toprovide sufficient travel for engagement of a radial seal between thefilter element 302 and the housing 320 via the disposition of the filterelement 302 in first housing end 128. As will be appreciated, thealignment of the specific alignment portions 304, 306 and 322, 326 makesit difficult, if not impossible, to radially—or axially—seal withoutusing a filter that matches the housing 320. While the alignment portion304 of the filter element 302 and the alignment portion 322 of thehousing 320 are shown to align and engage, in some arrangements, thealignment portion 304 of the filter element 302 and the alignmentportion 322 of the housing 320 only need to align, and not engage (e.g.,a gap may exist), to provide for the engagement of the radial sealbetween the filter element 302 and the housing 320.

Referring to FIG. 4A, a perspective view of a filter element 402 isshown, according to another example embodiment. The filter element 402is similar to the filter element 102. A difference between the filterelement 402 and the filter element 102 is the arrangement of alignmentportions of the filter element 402. Accordingly, like numbering is usedto designate like parts between the filter element 402 and the filterelement 102. As shown in FIG. 4A, the arrangement of the alignmentportion 404 of the filter element 402 comprises a plurality of (e.g.,four) helical inlets formed on the first end cap 106. The helical inletsalignment portion 404 of the filter element 402 has a varying heightrelative to the substantially lateral planar surfaces that aresubstantially normal to the central axis of the filter element 402. Inother words, the alignment portion 404 has alternating protrusions thatincrease to a peak and decrease into the flat, substantially lateralplanar portions of the first end cap 106 of the filter element 402. Eachof the helical inlets alignment portion 404 has a matching contouringsurface at locations on opposite sides of the first end cap 106 of thefilter element 402. As will be appreciated, the first end cap 106 andalignment portion 404 align with a housing having complementaryalignment portions to provide sufficient travel for engagement of aradial seal between the filter element 402 and the housing.

The filter element 402 further includes a second end cap 110 and filtermedia 108. Although the filter media is shown arranged as a cylindricalfilter block having a circular cross-sectional shape, the filter media108 can be arranged in other shapes. The filter element 402 issubstantially rigid such that the shape of the filter element 402 ismaintained. The rigidity may be achieved through the use of a frame(e.g., a hard urethane frame, an injection molded frame, a thermoformedframe, a roto-molded frame, a 3D printed frame, a stamped metal frame,etc.) or stiffening members (e.g., pleating stabilization beads,spraying with a stiffening agent, such as BASF® Elastocast 55090,polyurethane, or the like, etc.).

Referring to FIG. 4B, a perspective view of a housing 420 complementaryto the filter element 402 of FIG. 4A is shown. The housing 420 issimilar to the housing 120. A difference between the housing 420 and thesimilar housing 120 is the arrangement of a plurality (e.g., four)helical inlets as the alignment portion 424 of the housing 420.Accordingly, like numbering is used to designate like parts between thehousing 420 and the housing 120. As shown in FIG. 4B, the housing 420includes an alignment portion 424, the inlet tube 124, the outlet tube126, a first housing end 128, and a second housing end 129. The helicalinlets alignment portion 424 of the housing 420 is a surfacecomplementary to the helical inlets alignment portion 404 of the filterelement 402. As will be appreciated, the helical inlets alignmentportion 424 of the housing is interchangeable with the four helicalinlets alignment portion 404 of the filter element 402 such that thefilter element 402 can only be installed in four orientations.

The outlet tube 126 protrudes into the cylindrical housing 420 innervolume and the first housing end 128 profile matches the profile of theoutlet tube 126 and helical inlets alignment portion 424 contour.Although the housing 420 is shown arranged as a cylindrical housinghaving a circular cross-sectional shape, the housing 420 can be arrangedin other shapes to receive the filter element 402. Additionally, thematching surface (e.g., ramp) feature of the helical inlets alignmentportion 424 can improve tangential pre-cleaning.

Referring to FIG. 4C, a cross-sectional, side view of a filtrationsystem 400 is shown. The filtration system 400 includes the filterelement 402 of FIG. 4A, the housing 420 of FIG. 4B, and a housing cover130. When the filtration system 400 is in the assembled state, thefilter element 402 is positioned within a central compartment of thehousing 420. In some arrangements, the housing cover 130 is sealinglyengaged with the second end cap 110 of the filter element 402 and thesecond housing end 129 of the housing 420. As shown in FIG. 4C, thehousing cover 130 is a closed end cap, however, in other embodiments,the housing cover 130 is an open end cap. In some arrangements, asealing member contacts the second housing end 129 of the housing suchthat when the top housing cover 130 is secured to the housing 420, theseal member is compressed between the housing 420 and the top housingcover 130 to form a seal.

As shown in FIG. 4C, the helical inlets alignment portion 424 of thehousing 420 are in the form of a plurality of contoured surface thatprotrude and depress complementary to the raised and depressed surfacesof four helical inlets alignment portion 404 of the filter element 402.As shown in FIG. 4C, the helical inlets alignment portion 404 of thefilter element 402 and the complementary helical inlets alignmentportion 424 of the housing 420 align to provide sufficient travel forengagement of a radial seal between the filter element 402 and thehousing 420. As will be appreciated, the alignment of the alignmentportions 404 and 424 makes it difficult, if not impossible, to radiallyor axially seal without using a filter that matches the housing. Whilethe alignment portion 404 of the filter element 402 and the alignmentportion 422 of the housing 420 are shown to align and engage, in somearrangements, the alignment portion 404 of the filter element 402 andthe alignment portion 422 of the housing 420 only need to align, and notengage (e.g., a gap may exist), to provide for the engagement of theradial seal between the filter element 402 and the housing 420. In somearrangements, the radial seal is formed at the location of theengagement of the center of the vertical axis of the filter housing 420wall and the filter element 402.

Referring to FIG. 5A, a perspective view of a filter element 502 isshown, according to another example embodiment. The filter element 502is similar to the filter element 102. A difference between the filterelement 502 and the filter element 102 is the arrangement of analignment portion and the disposition on the filter element 502.Accordingly, like numbering is used to designate like parts between thefilter element 502 and the filter element 102. As shown in FIG. 5A, thearrangement of the alignment portion 504 on the second end cap 110 ofthe filter element 502 is a substantially angled surface that is notnormal to the central axis of the filter element 502. In other words,the filter element 502 has a varying, angled height which increasesalong the horizontal plane of the second end cap 110 of the filterelement 502. As will be appreciated, the angled surface of the alignmentportion 504 aides a 90° outlet tube on a complementary housing. In someembodiments, the alignment portion 504 is disposed on the first end cap106 of the filter element 502. As will be appreciated, the second endcap 110 and alignment portion 504 align with a housing having acomplementary alignment portion align to provide sufficient travel forengagement of a radial seal between the filter element 502 and thehousing 520. The alignment portion 504 comprises an ellipticalprotrusion. In some arrangements, the radial seal is formed at thelocation of the engagement of the center of the vertical axis of thefilter housing 520 wall and the filter element 502.

The filter element 502 further includes a first end cap 106 and filtermedia 108. Although the filter media is shown arranged as a cylindricalfilter block having a circular cross-sectional shape, the filter media108 can be arranged in other shapes. The urethane on the filter endcapis also angled such that more filter media 108 is exposed more on thelong side of the filter element 502 than on the short side, resulting inmore usable filter media 108 area. Accordingly, this variation resultsin lower restriction and higher dust capacity of the filter element 502.The filter element 502 is substantially rigid such that the shape of thefilter element 502 is maintained. The rigidity may be achieved throughthe use of a frame (e.g., a hard urethane frame, an injection moldedframe, a thermoformed frame, a roto-molded frame, a 3D printed frame, astamped metal frame, etc.) or stiffening members (e.g., pleatingstabilization beads, spraying with a stiffening agent, such as BASF®Elastocast 55090, polyurethane, or the like, etc.).

Referring to FIG. 5B, a perspective view of a housing 520 complementaryto the filter element 502 of FIG. 5A is shown. The housing 520 issimilar to the housing 120. A difference between the housing 520 and thesimilar housing 120 is the arrangement of an angled surface on thealignment portion 524 of the housing 520. Accordingly, like numbering isused to designate like parts between the housing 520 and the housing120. As shown in FIG. 5B, the housing 520 includes an alignment portion524, the inlet tube 124, the outlet tube 126, a first housing end 528,and a second housing end 529. The angled alignment portion 524 of thehousing 520 is a surface complementary to the angled alignment portion504 of the filter element 502. As will be appreciated, the angledalignment portion 524 comprises an elliptical groove and acts as akeying feature so that the filter element 502 can only be installed inone orientation. In some embodiments, the alignment portion 524 may bein the form of a depressed surface and varies in height due to thecontoured surfaces.

The outlet tube 126 protrudes into the cylindrical housing 520 innervolume and the first housing end 528 profile matches the profile of theoutlet tube 126 and the angled alignment portion 524 contour. The angledalignment portion 524 formed on the first housing end 528 of the housing520 has a constant height from the angled surface such that bottom ofthe housing 520 is also angled with respect to an axial surfacesubstantially normal to the central axis. Additionally, the surfacesthat align—to provide sufficient travel for engagement of a radial sealbetween the filter element 502 and the housing 520—are extruded in adirection that is substantially parallel to the central axis of thehousing 520. Although the housing 520 is shown arranged as a cylindricalhousing having a circular cross-sectional shape, the housing 520 can bearranged in other shapes to receive the filter element 502.

Referring to FIG. 5C, a perspective view of an assembled filtrationsystem 500 is shown, according to an example embodiment. The filtrationsystem 500 includes the filter element 502 of FIG. 5A (not shown), thehousing 520 of FIG. 5B, and a housing cover 530. When the filtrationsystem 500 is in the assembled state, the filter element 502 ispositioned within a central compartment of the housing 520. In somearrangements, the housing cover 530 is sealingly engaged with the firstend cap 106 of the filter element 502 and the second housing end 529 ofthe housing 520. As shown in FIG. 5C, the housing cover 530 is a closedend cap, however, in other embodiments, the housing cover 530 is an openend cap. In some arrangements, a sealing member contacts the secondhousing end 129 of the housing 520 such that when the top housing cover530 is secured to the housing 520, the seal member is compressed betweenthe housing 520 and the top housing cover 530 to form a seal.

Referring to FIG. 5D, a cross-sectional, side view of a portion of thefiltration system 500 of FIG. 5C is shown. The filtration system 500includes the filter element 502 of FIG. 5A, the housing 520 of FIG. 5B,and a housing cover 530. When the filtration system 500 is in theassembled state, the filter element 502 is positioned within a centralcompartment of the housing 520. As shown in FIG. 5D, the filter element502 and the complementary housing 520 align to provide sufficient travelfor engagement of a radial seal between the filter element 502 and thehousing 520. The top of the seal formed by the alignment of the angledalignment portion 524 of the housing 520 with the angled alignmentportion 504 of the filter element 502 is not at a substantially constantdepth with respect to the central axis. As will be appreciated, thealignment of the alignment portions 504 and 524 makes it difficult, ifnot impossible, to form a radial seal without using a filter thatmatches the housing. While the alignment portion 504 of the filterelement 502 and the alignment portion 522 of the housing 520 are shownto align and engage, in some arrangements, the alignment portion 504 ofthe filter element 502 and the alignment portion 522 of the housing 520only need to align, and not engage (e.g., a gap may exist), to providefor the engagement of the radial seal between the filter element 502 andthe housing 520. The alignment portion 504 on the second end cap 110forms a nonzero angle 540 with a longitudinal axis of the filtrationsystem 500.

Referring to FIG. 6A, a perspective view of a filter element 602 isshown, according to another example embodiment. The filter element 602is similar to the filter element 102. Differences between the filterelement 602 and the filter element 102 are the arrangement of analignment portion and the disposition on the filter element 602.Accordingly, like numbering is used to designate like parts between thefilter element 602 and the filter element 102. As shown in FIG. 6A, thearrangement of the alignment portion 604 disposed on the first end cap606 of the filter element 602 is an angled axial surface with respect tothe central axis that is beneficial for installation of side loadelements or filtration system. In other words, the filter element 602has a varying, angled height which increases along the horizontal planeof the first end cap 606 of the filter element 602. As will beappreciated, the first end cap 606 and alignment portion 604 align witha housing having a complementary alignment portion to provide sufficienttravel for engagement of a radial seal between the filter element 602and the housing. The radial seal formed is not extruded in a directionsubstantially parallel to the central axis, instead, the radial seal isin a direction substantially normal to the angled alignment portion 604.

The filter element 602 further includes a second end cap 110 and filtermedia 108. Although the filter media is shown arranged as a cylindricalfilter block having a circular cross-sectional shape, the filter media108 can be arranged in other shapes. The urethane on the filter endcapis also angled such that more filter media 108 is exposed more on thelong side of the filter element 602 than on the short side, resulting inmore usable filter media 108 area. Accordingly, this variation resultsin lower restriction and higher dust capacity of the filter element 602.The filter element 602 is substantially rigid such that the shape of thefilter element 602 is maintained. The rigidity may be achieved throughthe use of a frame (e.g., a hard urethane frame, an injection moldedframe, a thermoformed frame, a roto-molded frame, a 3D printed frame, astamped metal frame, etc.) or stiffening members (e.g., pleatingstabilization beads, spraying with a stiffening agent, such as BASF®Elastocast 55090, polyurethane, or the like, etc.).

Referring to FIG. 6B, a perspective view of a housing 620 complementaryto the filter element 602 of FIG. 6A is shown. The housing 620 issimilar to the housing 120. A difference between the housing 620 and thesimilar housing 120 is the arrangement of an angled surface on thealignment portion 624 of the housing 620 and the absence of the inlettube 124. Accordingly, like numbering is used to designate like partsbetween the housing 620 and the housing 120. As shown in FIG. 6B, thehousing 620 includes an angled alignment portion 624, an outlet tube126, an angled first housing end 628, and a second housing end 129. Theangled alignment portion 624 of the housing 620 is a surfacecomplementary to the angled alignment portion 604 of the filter element602. As will be appreciated, the angled alignment portion 624 acts as akeying feature so that the filter element 602 can only be installed inone orientation. In some embodiments, the alignment portion 624 may bein the form of a depressed surface and varies in height due to thecontoured surfaces.

The outlet tube 126 protrudes into the cylindrical housing 620 innervolume and the angled first housing end 628 profile matches the profileof the outlet tube 126 and the angled alignment portion 624 contour. Theangled alignment portion 624 of the housing 620 has a constant heightfrom the angled surface such that bottom of the housing 620 is alsoangled with respect to an axial surface substantially normal to thecentral axis. Additionally, the surfaces that align to providesufficient travel for engagement of a radial seal between the filterelement 602 and the housing 620 are not extruded in a direction that issubstantially parallel to the central axis of the housing 620. Instead,the alignment of the alignment portions 604, 624 is in a directionsubstantially normal to the angled surface of the alignment portion 624.Although the housing 620 is shown arranged as a cylindrical housinghaving a circular cross-sectional shape, the housing 620 can be arrangedin other shapes to receive the filter element 602.

Referring to FIG. 6C, a perspective view of an assembled filtrationsystem 600 is shown. The filtration system 600 includes the filterelement 602 of FIG. 6A (not shown), the housing 620 of FIG. 6B, an inletpiece 640, and a housing cover 630. When the filtration system 600 is inthe assembled state, the filter element 602 is positioned within acentral compartment of the housing 620. The housing cover 630 providesadditional locking and support of the filter element 602 and the housing620. In some arrangements, the housing cover 630 is integrally formed onthe side of the filter element 602. The inlet piece 640 is engaged withthe second end cap 110 of the filter element 602, the second housing end129 of the housing 620, and the housing cover 630. As shown in FIG. 6C,the inlet piece 640 is an open end with the inlet tube 124. However, inother embodiments, the inlet piece 640 is a closed end piece. In somearrangements, a sealing member contacts the second housing end 129 ofthe housing 620 such that when the top housing cover 630 is secured tothe housing 620, the seal member is compressed between the housing 620and the top housing cover 630 to form a seal.

Referring to FIG. 6D, a cross-sectional, side view of a portion of thefiltration system 600 of FIG. 6C is shown. As shown in FIG. 6D, thefiltration system 600 includes the filter element 602 of FIG. 6A, thehousing 620 of FIG. 6B, and housing cover 630. When the filtrationsystem 600 is in the assembled state, the filter element 602 ispositioned within a central compartment of the housing 620. As shown inFIG. 6D, the filter element 602 and the complementary housing 620 alignto provide sufficient travel for engagement of a radial seal between thefilter element 602 and the housing 620. The top of the radial sealformed by the alignment of the angled alignment portion 624 of thehousing 620 with the angled alignment portion 604 of the filter element602 is not at a constant depth in a direction substantially normal tothe angled surface. As will be appreciated, the engagement of thealignment portions 604 and 624 makes it difficult, if not impossible, toform a radial seal without using a filter that matches the housing.While the alignment portion 604 of the filter element 602 and thealignment portion 622 of the housing 620 are shown to align and engage,in some arrangements, the alignment portion 604 of the filter element602 and the alignment portion 622 of the housing 620 only need to align,and not engage (e.g., a gap may exist), to provide for the engagement ofthe radial seal between the filter element 602 and the housing 620. Insome arrangements, the radial seal is formed at the location of theengagement of the center of the vertical axis of the filter housing 620wall and the filter element 602.

Referring to FIG. 7A, a perspective view of an assembled filtrationsystem 700 is shown, according to another example embodiment. Thefiltration system 700 is similar to the filtration system 100 of FIG.1C. A difference between the filtration system 700 and the similarfiltration system 100 is the arrangement of an angled surface on thealignment portions of the housing and filter element and the use of anangled endcap with a sealing member. Accordingly, like numbering is usedto designate like parts between the filtration system 700 and thefiltration system 100. As shown in FIG. 7A, the filtration system 700includes a housing 720 and housing cover 730. The housing 720 includesan inlet tube 124, an outlet tube 126, a first housing end 726, and asecond housing end 129. In some arrangements, the housing cover 730 issealingly engaged with the second housing end 129. As shown in FIG. 7A,the housing cover 730 is a closed cover. However, in other embodiments,the housing cover 730 is an open cover. In some arrangements, a sealingmember contacts the second housing end 129 such that when the tophousing cover 730 is secured to the second housing end 129, the sealmember is compressed between the second housing end 129 and the tophousing cover 730 to form a seal.

Referring to FIG. 7B, a cross-sectional, side view of the filtrationsystem 700 of FIG. 7A is shown. As shown in FIG. 7B, the filtrationsystem 700 includes a filter element 702, the housing 720 of FIG. 7A,the housing cover 730, and an angled sealing member 728. When thefiltration system 700 is in the assembled state, the filter element 702is positioned within a central compartment of the housing 720. Thefilter element 702 includes filter media 108 disposed between an angledfirst end cap 706 and a second end cap 110. As shown in FIG. 7B, anangled alignment portion 704 disposed on the angled first end cap 706 ofthe filter element 702 aligns with an angled alignment portion 724disposed on the first housing end 726. The angled first end cap 706seals on the radial outer diameter of the angled first end cap 706 andseals on the radial inner diameter of the first housing end 726. Theseal between the angled first end cap 706 and housing 720 may be aidedby using the angled sealing member 728 in the form of a gasket or anO-ring. In some embodiments, the angled first end cap 706 may be mediaembedded or potted. As shown in FIG. 7B, the angled alignment portion724 of the housing 720 and the angled alignment portion 704 of theangled outlet end cap 706 align to provide sufficient travel forengagement of a radial seal between the filter element 702 and thehousing 720. As will be appreciated, the alignment of the alignmentportions 704 and 724 makes it difficult, if not impossible, to radiallyor axially seal without using a filter that matches the housing. Whilethe alignment portion 704 of the filter element 702 and the alignmentportion 722 of the housing 720 are shown to align and engage, in somearrangements, the alignment portion 704 of the filter element 702 andthe alignment portion 722 of the housing 720 only need to align, and notengage (e.g., a gap may exist), to provide for the engagement of theradial seal between the filter element 702 and the housing 720. In somearrangements, the radial seal is formed at the location of theengagement of the center of the vertical axis of the filter housing 720wall and the filter element 702.

Referring to FIG. 8A, a cross-sectional, perspective view of afiltration system 800 including a keyed center tube interface is shown,according to a further example embodiment. The filtration system 800 issimilar to the filtration system 100 of FIG. 1C. A difference betweenthe filtration system 800 and the similar filtration system 100 is theuse of a keyed center tube interface to align datum seal planes to theproper location. Accordingly, like numbering is used to designate likeparts between the filtration system 800 and the filtration system 100.As shown in FIG. 8A, the filtration system 800 includes the filterelement 802, the housing 120, a housing cover 130, and a keyed centertube 828 integral to the filter element 802.

The filter element 802 includes a first end cap 106 has a laterallyplanar surface that is substantially normal to the central axis of thefilter element 802 and an alignment portion (e.g., alignment surface,protrusion, etc.) 104 in the form of a contoured surface that issubstantially parallel to the central axis of the filter element 102. Inother words, the contoured surface is extruded in a directionperpendicular to the central axis such that a portion of the surface isin a direction normal to the central axis and a portion of the surface(e.g., direction of indentation) is in a direction parallel to thecentral axis of the filter element 802. As shown in FIG. 8A, thealignment portion 104 is a depressed surface. Additionally, the filterelement 802 has a keyed center tube 828 that is integral to the filterelement 802. The housing 120 includes an alignment portion 122, an inlettube 124, an outlet tube 126, a first housing end 128, and a secondhousing end 129. The alignment portion 122 is a surface complementary tothe alignment portion 104 of the filter element 802. As will beappreciated, the first end cap 106 and alignment portion 104 align withthe complementary alignment portion 122 of the housing 120 to providesufficient travel for engagement of a radial seal between the filterelement 802 and the housing 120.

The keyed center tube 828 is potted in urethane and is integral to thefilter element 802. The keyed center tube 828 is structured with a keyedinterface that aligns and seals into the proper location. The keyedcenter tube 828 is structured to align itself to the angled step changeof the alignment portion 122 of the housing 120. The inner diameter tothe keyed center tube 828 is less than the inner diameter of theurethane, protruding inward. This additional radial inward protrusionallows the keyed center tube 828 to interface with a radial sealing wallof the housing 120. When installing the element, the keyed center tube828 first makes contact with the sealing wall before the filter element802 makes contact with the surface of the first housing end 128. Thisaides in ensuring the filter element 802 is located in the correctorientation because the keyed center tube 828 can easily slide on thewall (e.g. plastic to plastic interface) allowing a user to rotate thefilter element 802 until it reaches the correct position. Without thisinterface, the bottom of the filter element 802 would need to slideagainst the bottom surface of the first housing end 128 resulting inhigher friction (urethane to plastic contact). In some embodiments, thekeyed center tube 828 comprises a protruding rib and there is acorresponding slot for the protruding rib on the housing 120. In somearrangements, the keyed center tube 828 is integrated into an end cap106, 110 of the filter element 802 for potting or embedding.

Referring to FIG. 8B, a cross-sectional, perspective view of afiltration system 850 including a including a center tube interface isshown, according to another further example embodiment. The filtrationsystem 850 is similar to the filtration system 800 of FIG. 8A. Adifference between the filtration system 850 and the similar filtrationsystem 800 is the use of a center tube that is integral to thehousing—via molding, welding, or snap fit—instead of the filter element.Accordingly, like numbering is used to designate like parts between thefiltration system 850 and the filtration system 800. As shown in FIG.8B, the filtration system 850 includes a filter element 102, a housing820, a housing cover 130, and a center tube 852 integral to the housing820.

The filter element 102 includes filter media 108 disposed between afirst end cap 106 and a second end cap 110. The first end cap 106 has asubstantially lateral planar surface that is substantially normal to thecentral axis of the filter element 102 and an alignment portion (e.g.,alignment surface, protrusion, etc.) 104 in the form of a contouredsurface that is substantially parallel to the central axis of the filterelement 102. As shown in FIG. 8B, the alignment portion 104 is adepressed surface. The housing 820 includes an alignment portion 122, aninlet tube 124, an outlet tube 126, a first housing end 128, and theintegral center tube 852. The alignment portion 122 is a surfacecomplementary to the alignment portion 104 of the filter element 102. Aswill be appreciated, the first end cap 106 and alignment portion 104aligns with the complementary alignment portion 122 of the housing 820to provide sufficient travel for engagement of a radial seal between thefilter element 102 and the housing 820.

The integral center tube 852 is molded integral to the housing 820 orengaged via a snap fit connection. The integral center tube 852 has akeyed interface in the axial direction that has a complementary surfacein the filter element 102. The keyed interface of the integral centertube 852 engages the second end cap 110 of the filter element 102 andaligns to the proper location on the filter element 102 to sealinglyengage. The inner diameter to the integral center tube 852 is less thanthe inner diameter of the urethane, protruding inward. If the filterelement 102 is misaligned, the housing cover 130 will not properly sealdue to the keyed interface of the integral center tube 852 beingmisaligned.

Referring to FIG. 9A, a cross-sectional, side view of a filtrationsystem 900 including a central sealing rib is shown, according to afurther example embodiment. The filtration system 900 is similar to thefiltration system 100 of FIG. 2. Differences between the filtrationsystem 900 and the similar filtration system 100 include the absence ofan angled alignment portion and the use of a central sealing rib.Accordingly, like numbering is used to designate like parts between thefiltration system 900 and the filtration system 100. As shown in FIG.9A, the filtration system 900 includes a filter element 902 and ahousing 920. The filter element 902 includes a filter media 108, asecond end cap 110, a first end cap 106, and an alignment portion 904 onthe first end cap 106 in the form of a recess to receive a complementaryfeature of the housing 920.

As shown in FIG. 9A, the housing 920 includes an outlet tube 126 and aflexible rib 922. The flexible rib 922 is structured to align with thecomplementary surface of the alignment portion 904 of the filter element902. The flexible rib 922 is not rigid enough to seal only one side ofthe filter element 902 and housing 920, thus the flexible rib 922 isdisposed on multiple sides of the housing 920 to engage with the filterelement 902 at multiple points. The radial seal occurs on the innerdiameter and the outer diameter of the flexible rib 922. In someembodiments, the flexible rib 922 is integrally formed with the housing920. One example embodiment of the housing 920 is shown in FIG. 9B. Thehousing 920 includes a circular, crisscross pattern of the flexible rib922. The flexible rib 922 extends all the way out to the housing 920wall and tube of the outlet tube 126 to require sealing on both sidesand, beneficially, forms a seal between the filter element 902 and thehousing 920.

Referring to FIG. 9C, a cross-sectional, side view of a filtrationsystem 930 including a central sealing rib is shown, according to afurther example embodiment. The filtration system 930 is similar to thefiltration system 900 of FIG. 9A. A difference between the filtrationsystem 930 and the similar filtration system 900 is the differentconfiguration of the flexible rib and sealing engagement. Accordingly,like numbering is used to designate like parts between the filtrationsystem 930 and the filtration system 900. As shown in FIG. 9C, thefiltration system 930 includes a filter element 932 and a housing 940.The filter element 932 includes a filter media 108, a second end cap110, a first end cap 106, and an alignment portion 934 on the first endcap 106 in the form of a recess to receive a complementary featurealignment portion 942 of the housing 940.

As shown in FIG. 9C, the housing 940 includes an outlet tube 126 and acentral rib 942. The central rib 942 includes an inner diameter surface944 and an outer diameter surface 946 that are structured to align witha complementary surface of the alignment portion 934 of the filterelement 932. The central rib 942 is slanted such that the inner diametersurface 944 is a vertical wall and the outer diameter surface 946 is anangled surface. The central rib 942 is disposed on multiple side of thehousing 940 and is structured to align with engage with the filterelement 902 at multiple points. As will be appreciated, sealing onlyoccurs on the angled surface of the outer diameter surface 946. Theinner diameter surface 944 is only used for generating the retentionforce to retain the filter element 932 in the housing 940. In somearrangements, the central rib 942 needs only to align, and not engage(e.g., a gap may exist), with the filter element 902 to provide for theengagement of the radial seal.

It should be noted that any use of the term “example” herein to describevarious embodiments is intended to indicate that such embodiments arepossible examples, representations, and/or illustrations of possibleembodiments (and such term is not intended to connote that suchembodiments are necessarily extraordinary or superlative examples).

As utilized herein, the term “substantially” and similar terms areintended to have a broad meaning in harmony with the common and acceptedusage by those of ordinary skill in the art to which the subject matterof this disclosure pertains. It should be understood by those of skillin the art who review this disclosure that these terms are intended toallow a description of certain features described and claimed withoutrestricting the scope of these features to the precise numerical rangesprovided. Accordingly, these terms should be interpreted as indicatingthat insubstantial or inconsequential modifications or alterations ofthe subject matter described and claimed (e.g., within plus or minusfive percent of a given angle or other value) are considered to bewithin the scope of the invention as recited in the appended claims. Theterm “approximately” when used with respect to values means plus orminus five percent of the associated value.

The terms “coupled” and the like as used herein mean the joining of twomembers directly or indirectly to one another. Such joining may bestationary (e.g., permanent) or moveable (e.g., removable orreleasable). Such joining may be achieved with the two members or thetwo members and any additional intermediate members being integrallyformed as a single unitary body with one another or with the two membersor the two members and any additional intermediate members beingattached to one another.

References herein to the positions of elements (e.g., “top,” “bottom,”“above,” “below,” etc.) are merely used to describe the orientation ofvarious elements in the FIGURES. It should be noted that the orientationof various elements may differ according to other example embodiments,and that such variations are intended to be encompassed by the presentdisclosure.

It is important to note that the construction and arrangement of thevarious example embodiments are illustrative only. Although only a fewembodiments have been described in detail in this disclosure, thoseskilled in the art who review this disclosure will readily appreciatethat many modifications are possible (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Forexample, elements shown as integrally formed may be constructed ofmultiple parts or elements, the position of elements may be reversed orotherwise varied, and the nature or number of discrete elements orpositions may be altered or varied. The order or sequence of any processor method steps may be varied or re-sequenced according to alternativeembodiments. Additionally, features from particular embodiments may becombined with features from other embodiments as would be understood byone of ordinary skill in the art. Other substitutions, modifications,changes and omissions may also be made in the design, operatingconditions and arrangement of the various example embodiments withoutdeparting from the scope of the present invention.

What is claimed is:
 1. A filtration system, comprising: a housing havinga first housing end and a second housing end and defining a centralcompartment therein, the housing comprising a first alignment portiondisposed on the first housing end; and a filter element positionedwithin the central compartment of the housing, the filter element havinga first filter end and a second filter end, the filter elementcomprising: filter media; and a second alignment portion disposed on thefirst filter end, the second alignment portion complementary to thefirst alignment portion, the second alignment portion comprising a firstsurface and a second surface, the second alignment portion having avariable cross-section such that a distance between the first surfaceand the second surface varies along at least a portion of the secondalignment portion, the variable cross-section being complementary to thefirst alignment portion of the housing such that the second alignmentportion aligns with the first alignment portion of the housing toprovide for engagement of a radial seal between the filter element andthe housing when the filter element is properly installed within thehousing, the second alignment portion including a plurality of curvedprotrusions.
 2. The filtration system of claim 1, wherein the pluralityof curved protrusions comprise a plurality of helical protrusions. 3.The filtration system of claim 1, wherein the first filter end furthercomprises a substantially lateral planar portion, at least one curvedprotrusion of the plurality of curved protrusions comprising an angledportion that increases into a peak and decreases into the substantiallylateral planar portion.
 4. The filtration system of claim 1, wherein aheight of the radial seal between the housing and the filter elementvaries along a circumferential direction relative to a central axis ofthe housing.
 5. The filtration system of claim 1, wherein the housingcomprises an angled inner sealing wall that is structured to sealinglyengage with the filter element, a height of the angled inner sealingwall varies along a circumferential direction relative to a central axisof the housing.
 6. The filtration system of claim 1, wherein the firstfilter end further comprises a substantially lateral planar surface thatis substantially normal to a central axis of the filter element, atleast one of the plurality of curved protrusions extending away from thesubstantially lateral planar surface and having a height that variesrelative to the substantially lateral planar surface.
 7. The filtrationsystem of claim 1, wherein the first filter end further comprises asubstantially lateral planar surface that is substantially normal to acentral axis of the filter element, wherein a first curved protrusion ofthe plurality of curved protrusions is spaced apart from a second curvedprotrusion of the plurality of curved protrusions by the substantiallylateral planar surface.
 8. The filtration system of claim 1, wherein thehousing comprises an end cap, the first alignment portion of the housingdisposed on the end cap.
 9. A filtration system, comprising: a housinghaving a first housing end and a second housing end and defining acentral compartment therein, the housing comprising a first alignmentportion disposed on the first housing end; and a filter elementpositioned within the central compartment of the housing, the filterelement having a first filter end and a second filter end, the filterelement comprising: filter media; and a second alignment portiondisposed on the first filter end, the second alignment portioncomplementary to the first alignment portion, the second alignmentportion comprising a first surface and a second surface, the secondalignment portion having a variable cross-section such that a distancebetween the first surface and the second surface varies along at least aportion of the second alignment portion, the variable cross-sectionbeing complementary to the first alignment portion of the housing suchthat the second alignment portion aligns with the first alignmentportion of the housing to provide for engagement of a radial sealbetween the filter element and the housing when the filter element isproperly installed within the housing, the filter element furthercomprising a center tube axially extending from the first filter end tothe second filter end, the center tube comprising a first tube end and asecond tube end, the first tube end having a shape similar to the secondalignment portion, the second tube end configured to engage an end capon the second filter end, the end cap being rotatable to align thefilter element within the housing.
 10. The filtration system of claim 9,wherein a height of the radial seal between the housing and the filterelement varies along a circumferential direction relative to a centralaxis of the housing.
 11. The filtration system of claim 9, wherein thehousing comprises an angled inner sealing wall that is structured tosealingly engage with the filter element, a height of the angled innersealing wall varies along a circumferential direction relative to acentral axis of the housing.
 12. The filtration system of claim 9,wherein the housing comprises a radial sealing wall extending away fromthe first housing end, the first tube end comprising a keyed interfacethat is configured to engage with the radial sealing wall.
 13. Thefiltration system of claim 12, wherein the first filter end comprises afirst end cap, the keyed interface protruding radially inward from thefirst end cap.
 14. The filtration system of claim 12, wherein the aheight of the radial sealing wall varies along a circumferentialdirection relative to a central axis of the housing, the keyed interfacestructured to align with the radial sealing wall to provide forengagement of the radial seal when the filter element is properlyinstalled within the housing.
 15. A filtration system, comprising: ahousing having a first housing end and a second housing end and defininga central compartment therein, the housing comprising a first alignmentportion disposed on the first housing end; and a filter elementpositioned within the central compartment of the housing, the filterelement having a first filter end and a second filter end, the filterelement comprising: filter media; and a second alignment portiondisposed on the first filter end, the second alignment portioncomplementary to the first alignment portion, the second alignmentportion comprising a first surface and a second surface, the secondalignment portion having a variable cross-section such that a distancebetween the first surface and the second surface varies along at least aportion of the second alignment portion, the variable cross-sectionbeing complementary to the first alignment portion of the housing suchthat the second alignment portion aligns with the first alignmentportion of the housing to provide for engagement of a radial sealbetween the filter element and the housing when the filter element isproperly installed within the housing, the second alignment portioncomprising an elliptical groove, the first alignment portion comprisingan elliptical protrusion such that engagement of the elliptical grooveand the elliptical protrusion provides for engagement of the radial sealwhen the filter element is properly installed within the housing. 16.The filtration system of claim 15, wherein a height of the radial sealbetween the housing and the filter element varies along acircumferential direction relative to a central axis of the housing. 17.The filtration system of claim 15, wherein the housing comprises anangled inner sealing wall that is structured to sealingly engage withthe filter element, a height of the angled inner sealing wall variesalong a circumferential direction relative to a central axis of thehousing.
 18. The filtration system of claim 15, wherein the ellipticalgroove extends along a radial direction relative to a central axis ofthe filter element.
 19. The filtration system of claim 15, wherein theelliptical groove is one of a plurality of elliptical grooves, andwherein the elliptical protrusion is one of a plurality of ellipticalprotrusions that are shaped complementary with the plurality ofelliptical grooves.
 20. A filter element configured to be positionedwithin a central compartment of a housing, the filter element having afirst filter end and a second filter end, the filter element comprising:filter media; and a first alignment portion disposed on the first filterend, the first alignment portion configured to engage a complementarysecond alignment portion on the housing, the first alignment portioncomprising a first surface and a second surface, the first alignmentportion having a variable cross-section such that a distance between thefirst surface and the second surface varies along at least a portion ofthe first alignment portion, the variable cross-section beingcomplementary to the second alignment portion of the housing such thatthe first alignment portion aligns with the second alignment portion ofthe housing so as to provide for engagement of a radial seal between thefilter element and the housing when the filter element is properlyinstalled within the housing, the first alignment portion including aplurality of curved protrusions.
 21. The filter element of claim 20,wherein the plurality of curved protrusions comprise a plurality ofhelical protrusions.
 22. The filter element of claim 20, wherein thefirst filter end further comprises a substantially lateral planarportion, at least one curved protrusion of the plurality of curvedprotrusions comprising an angled portion that increases in to a peak anddecreases in to the substantially lateral planar portion.
 23. The filterelement of claim 20, wherein a height of a radial sealing surface of thefilter element varies along a circumferential direction relative to acentral axis of the filter element.
 24. The filter element of claim 20,wherein the first filter end further comprises a substantially lateralplanar surface that is substantially normal to a central axis of thefilter element, at least one of the plurality of curved protrusionsextending away from the substantially lateral planar surface and havinga height that varies relative to the substantially lateral planarsurface.
 25. The filter element of claim 21, wherein the plurality ofhelical protrusions comprises a first helical protrusion, a secondhelical protrusion, a third helical protrusion, and a fourth helicalprotrusion disposed around a central opening in the first filter end,the first helical protrusion disposed adjacent to the second helicalprotrusion and the fourth helical protrusion and disposed opposite ofthe third helical protrusion, the second helical protrusion disposedadjacent to the first helical protrusion and the third helicalprotrusion and disposed opposite of the fourth helical protrusion.